all continents are drifting back together

Remember in school when we were taught that all the continents of the Earth were at one time a single large supercontinent?  Now some scientists are saying we’re going back to that.  And not only that, but that this has happened before, many times, and each cycle is 500 million years.  So the continents all break apart, then eventually they all come back together in the middle.

What’s crazy is that the TV show that was saying this said it was like wooden continental plate models floating in boiling water.  They showed this, and the plates did drift apart.  But then they go about randomly, so it wasn’t really a good model after all.  It just didn’t seem too scientific.  But they’re the scientists, so we should believe everything they say, right?

Also, when the continents come back together, this will result in extreme climates, and it may be enough to wipe out some of life.  If that has happened multiple times, wouldn’t that throw a wrench in the theory of evolution?